Year	gross (GPI)
1970	1.44929003715515
1972	1.44418001174927
1973	1.41904997825623
1975	1.40568995475769
1976	1.40216994285583
1977	1.42191004753113
1978	1.43748998641968
1979	1.43325996398926
1980	1.41086995601654
1981	1.3745299577713
1982	1.33024001121521
1983	1.31235003471375
1984	1.28159999847412
1985	1.26626002788544
1986	1.25362002849579
1987	1.25155997276306
1988	1.24038004875183
1989	1.2251900434494
1990	1.22842001914978
1991	1.22107005119324
1992	1.20273995399475
1993	1.18877995014191
1994	1.17346000671387
1996	1.14705002307892
1997	1.12981998920441
1998	1.12911999225616
1999	1.10592997074127
2000	1.06070005893707
2001	1.04078996181488
2002	1.03949999809265
2003	1.03954005241394
2004	1.03164994716644
2005	1.03302001953125
2006	1.03237998485565
2007	1.03822004795074
2008	1.04358005523682
2009	1.05947995185852
2010	1.04917001724243
2011	1.04481995105743
2012	1.05025005340576
2013	1.04997003078461
2014	1.05063998699188
2015	1.04560005664825
2016	1.04343998432159
2017	1.04505002498627
2018	1.04179000854492
2019	1.04413771629333